using System;

namespace Sedna.Core.Persistence
{
	/// <summary>
	/// defines filter unset field strategy
	/// It is possible to either skip a field in a filter criteria (i.e. SQL where clause)
	/// if a particular filter property is not set
	/// or it is also possible to add that field with the equality to null criteria (i.e. ... where FIELD_A is NULL)
	/// </summary>
	public enum FilterUnsetStrategy
	{
		/// <summary>
		/// usually the default strategy.
		/// skips an unset property while building the SQL where clause
		/// </summary>
		Skip = 1,

		/// <summary>
		/// adds a corresponding field into a SQL where clause with the check for null (i.e. ...where FIELD_A is NULL)
		/// </summary>
		AddIsNull
	}
}
